Yin X Z, Ma C Y, Ye T C, Xiao S M, Jin Y H. A low-phase-noise LC-VCO with an enhanced-Q varactor for use in a high-sensitivity GNSS receiver[J]. J. Semicond., 2012, 33(5): 055002. doi: 10.1088/1674-4926/33/5/055002.
Yin Xizhen , Ma Chengyan , Ye Tianchun , Xiao Shimao and Jin Yuhua
Abstract: An LC-VCO with an enhanced quality factor (Q) varactor for use in a high-sensitivity GNSS receiver is presented. An enhanced A-MOS varactor is composed of two accumulation-mode MOS (A-MOS) varactors and two bias voltages, which show the improved Q and linearization capacitance-voltage (C-V) curve. The VCO gain (KVCO) is compensated by a digital switched varactors array (DSVA) over entire sub-bands. Based on the characteristics of an A-MOS, the varactor in a DSVA is a high Q fixed capacitor as it is switched off, and a moderate Q tuning varactor when it is switched on, which keeps the maximal Q for the LC-tank. The proposed circuit is fabricated in a 0.18 μm 1P6M CMOS process. The measured phase noise is better than -122 dBc/Hz at a 1 MHz offset while the measured tuning range is 58.2% and the variation of KVCO is close to ±21% over the whole of the sub-bands and the effective range of the control voltage. The proposed VCO dissipates less than 5.4 mW over the whole operating range from a 1.8 V supply.
Key words: A-MOS, voltage controlled oscillator, quality factor, VCO gain compensation, CMOS, CMOS
[1] | |
[2] | |
[3] | |
[4] | |
[5] | |
[6] | |
[7] | |
[8] | |
[9] | |
[10] | |
[11] | |
[12] | |
[13] | |
[14] | |
[15] | |
[16] |
Yin X Z, Ma C Y, Ye T C, Xiao S M, Jin Y H. A low-phase-noise LC-VCO with an enhanced-Q varactor for use in a high-sensitivity GNSS receiver[J]. J. Semicond., 2012, 33(5): 055002. doi: 10.1088/1674-4926/33/5/055002.
Article views: 2599 Times PDF downloads: 2774 Times Cited by: 0 Times
Manuscript received: 20 August 2015 Manuscript revised: 28 November 2011 Online: Published: 01 May 2012
Journal of Semiconductors © 2017 All Rights Reserved 京ICP备05085259号-2